Conveyor belt rip panels and belt rip monitoring

ABSTRACT

A conveyor belt rip monitoring system is disclosed. The system includes at least one rip panel having a conductive loop positioned in or on a conveyor belt so that the loop extends substantially across the width of the belt. The conductive loops may be formed from metallic or non-metallic materials. An RFDD chip is electrically coupled to the loop and provides a signal to an RFID interrogation unit positioned on the conveyor structure indicative of the health of the conductive loop. If a break is sensed in the loop, the RFID chip sends an appropriate signal to the interrogation unit which passes the information to a processing system. A unique resistor or diode may be included in the circuit between the chip(s) and the legs of the loop so that the interrogation unit can distinguish one leg or loop from another. If the break in the loop is determined to be due to a rip in the conveyor belt, the processing system alerts a user of the rip condition via an attached display device. For large scale rips the system may automatically stop the conveyor belt. Various embodiments of rip detection panels are also disclosed.

REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of International application No.PCT/GB2006/003190 filed Aug. 29, 2006, and U.S. Provisional Ser. Nos.61/098,389, 61/098,461 and 61/098,378, filed Sep. 19, 2008, each ofwhich is hereby incorporated by reference.

FIELD OF THE INVENTION

The invention relates to systems for monitoring industrial conveyor beltsystems, and more particularly to an improved rip panel for use indetecting longitudinal rips in conveyor belts and a system that employssuch a panel.

BACKGROUND

Conveyor belts and conveyor systems are widely used in the transport ofa variety of materials and products. Conveyor belts may be used in lightor heavy materials transport. For heavy materials transport often thebelts have reinforcing cords of steel or other material embedded in thebelt to provide additional tensile strength. For lighter materialtransport such reinforcing cords may be formed of lighter weightnon-metallic fibers or cords. In some lightweight applications noreinforcing cords are used.

Rip damage can arise in any of these belts during operation. Forexample, such a rip can occur when the belt is penetrated by an objectwhich has become jammed so that it does not move with the belt. As thebelt is driven forcibly against an object that penetrates the belt, alongitudinal rip may develop rapidly along an extended portion of thebelt. Such a condition can render the belt unsuitable for the continuedtransport of material so that the belt must be taken out of service. Inextreme cases, the whole belt may require replacement. In other cases,the damaged section must be repaired. As will be appreciated, this canresult in financial losses due to the cost of belt repair or replacementand the inconvenience of suspending manufacturing or other operationswhich rely on continued operation of the conveyor.

Various attempts have been made to provide a rip detection system whichcan promptly stop operation of a conveyor belt if a rip has occurred.One such prior assembly is shown diagrammatically in FIG. 2, which is atop plan view on a conveyer system belt 2 and hopper 10. Transmittersand receivers 5, 7 are mounted above the belt 2 near loading ordischarge sections where most belt rips occur. Antennae 3 are embeddedintermittently throughout the conveyor belt. The control box 9 receivespower from power source box 11 and sends a signal through thetransmitters to each antenna as it passes by the transmitter. The signalpasses through the antenna 3 back to the receiver and the control box.The control box receives the signal and evaluates the message. If thesignal doesn't reach the receiver, it means a belt tear has interruptedcurrent flow through the antenna 3. Lack of a transmitted signalindicates that damage has occurred to the belt, and the power to thebelt shut off by the control accordingly.

There are shortcomings, however, to such prior rip detection systems.Only one type of information is provided—signal or lack of a signal.Gradual decrease in signal strength, which could provide usefulinformation as to belt wear, for example, is not detectable. For priorsystems to operate effectively the transmitters and receivers must bepositioned a precise distance from the antennae and control box duringbelt operation; and in loading and discharge sections of the conveyorbelt, material may easily collide with the nearbytransmitter(s)/receiver(s) causing them to become misaligned with theantennae or to cease functioning altogether. Additionally, thetransmitters, receivers, and their corresponding electrical connectionscan fail or become undependable over time. Belt down time frequentlyoccurs as a result.

There is, therefore, a need for an improved rip detection system that iscost effective, reliable, and which does not itself impact the functionof the belt.

SUMMARY OF THE INVENTION

The disadvantages heretofore associated with existing rip detectionsystems are overcome by the disclosed design for a conveyor belt ripmonitoring system. Thus, a conveyor belt rip panel monitoring system isdisclosed, which includes: (1) a conductive loop, (2) a Radio FrequencyIdentification (RFID) chip electrically connected to the conductiveloop, (3) an RFID interrogator positioned to receive information aboutthe conductive loop from the RFID chip, (4) a processing systemassociated with the RFID interrogator for receiving a signal from theinterrogator and processing the signal to obtain a measure of theintegrity of the conductive loop, and (5) a user interface for providingan indication of the integrity of the conductive loop to a user.

The RFID interrogation unit can read and write to one RFID chip or aplurality of chips located on or in the belt. The RFID chip may alsoprovide to the interrogator information relating to a rip panelassociated with the belt. The rip panel information may include one ormore of the members of the group consisting of: rip panel modelinformation, rip panel brand/OEM information, rip panel age informationand rip panel repair history.

In another aspect of the invention, the conductive loop and the RFIDchip are connected to a rip detection panel, and the panel is positionedbetween layers of the conveyor belt. The belt may include a plurality ofrip panels, and the panels may be positioned at approximately 200 footintervals along the length of the belt.

A resistor or diode may be electrically connected to the conductive loopand the RFID chip. The conductive loop may be formed from a non-metallicconductive material. The non-metallic conductive loop may include aplurality of legs electrically coupled with the RFID chip. A pluralityof loops may be formed from a plurality of legs, and one leg of eachloop may be electrically connected to the RFID chip by a resistor ordiode having a different resistance so that the interrogator maydistinguish each of the loops from another.

The processing system may be a programmable logic controller (PLC) racksystem, and the interrogation unit may be connected to the processingsystem via an Ethernet switch. The system may be operably connected to adata communications network, which may comprise, for example, afacility-wide monitoring system, an Intranet, a virtual private networkor the Internet.

In still another aspect of the invention, the RED chip also provides tothe interrogator information relating to the model, brand/OEM, age andrepair history of the rip panel associated with the belt.

In yet another aspect of the invention, the system includes at least onecamera for transmitting visual information regarding the conveyor beltto a user.

A belt control system may also be operably connected to the monitoringsystem for directly or indirectly changing the operation of the conveyorbelt in response to the signal(s) from the interrogator.

One object of the invention is to provide an improved conveyor belt rippanel and belt rip monitoring system, which is capable of promptlyceasing operation of a conveyor belt if a rip has occurred. Anotherobject of the invention is to provide an improved rip detection systemthat is cost effective, reliable, and that does not itself impact thefunction of the belt. Related objects and advantages of the inventionwill be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the invention, both as to its structure and operation,may be obtained by a review of the accompanying drawings, in which likereference numerals refer to like parts, and in which:

FIG. 1 is a side partial diagrammatic view of an exemplary conveyor beltrip monitoring system;

FIG. 2 is a top plan view of a prior art rip detection system;

FIG. 3 is a cutaway perspective view of a conveyor belt showing anembodiment of the RFID chip and conductive loop of the inventionembedded in a layer of the belt;

FIG. 4 is a section view, taken along line 4-4 of FIG. 3, showing anembodiment of a rip panel with an associated RFID chip of the invention;

FIG. 5 is a plan view of an exemplary rip panel for use with theconveyor system of FIG. 1;

FIG. 5A is an enlarged plan view of the RFID chip of FIG. 5;

FIG. 6 is a plan view of another exemplary rip panel for use with theconveyor system of FIG. 1;

FIG. 7 is a plan view of a further exemplary rip panel for use with theconveyor system of FIG. 1; and

FIG. 8 is a section view, taken along line 8-8 of FIG. 5A, showing anembodiment of the RFID chip with material forming the belt extendingthrough a bore formed in the chip.

DETAILED DESCRIPTION

An improved system is disclosed for monitoring conveyor belts to detectrips that can occur in operation. Specifically, the disclosed systemwill detect early stages of longitudinal rips in conveyor belts so thatthe rips can be closely monitored and/or the belt can be stopped beforecatastrophic failure occurs.

Referring to FIG. 1, an exemplary conveyor belt rip monitoring system 1is shown. A conveyor system 2 may have a reinforced conveyor belt 4which extends around two end pulleys 6, 8. One of the two pulleys may bepowered by a motor to drive the belt. The belt 4 may pass under aloading hopper 10 such that material from the hopper 10 is transportedby the load-carrying working surface 12 of the belt 2 in a direction tothe left in FIG. 1. At one end pulley 6 the material falls into asecond, collection hopper 14.

At a position downstream of the loading hopper 10 and facing theunderside 16 of the belt 2 an RFID interrogation unit 18 is provided. Inone embodiment, the interrogation may comprise an antenna with areader/writer. It will be appreciated that although it is illustrated asbeing under the belt, one or more interrogation units 18 may be providedin any appropriate location with respect to the belt, as long as it canread one or more RFID chips located on or within the belt. The systemmay have more than one RFID interrogation unit 18. Where multiple units18 are provided, they may be positioned at particular locations ofinterest, such as at the beginning of the belt return section, or nearthe end pulley 6 at a position downstream of the unloading hopper 14. Aswill be described in greater detail later, the interrogation unit 18 maybe connected to a processing system 19 to enable processing ofinformation received from the interrogation unit. In one embodiment, theRFID interrogation unit 18 can read and write to one or more RFID chipslocated in or on the belt 2. For purposes of this description theaforementioned chip(s) may be an RFID chip electronically connected to aconductive loop as described below, or the chip(s) may include an RFIDchip located near or otherwise associated with a corresponding rippanel.

Referring now to FIGS. 3 and 4, exemplary conveyor belt 2 may have upperand lower rubber cover layers 20, 22 between which are sandwiched one ormore longitudinal reinforcement layers 24 of reinforcing cords embeddedin rubber. In some embodiments these reinforcing cords are made fromsteel, while in other embodiments they may be non-metallic materials.Yet other embodiments incorporate a fabric layer or no reinforcing layerat all. For belts utilizing one or more reinforcing layers 24, a ripdetection panel 26 may be positioned between one of the cover layers 20,22 and the reinforcement layer 24. The rip detection panel 26 may beassembled as a pre-formed strip in which all the elements of the panelare embedded in rubber or other flexible material. The strip may then bevulcanized into the belt during manufacture to ensure long term belt andpanel stability.

It will be appreciated that a conveyor belt 2 may be provided with anyappropriate number of such rip panels at longitudinally spaced intervalsalong the belt 2 in order to ensure that a rip in a section of belt isdetected before it becomes too large. In one embodiment, rip panels willbe positioned at approximately 200 foot intervals along the belt.

Referring now to FIGS. 3-5A, the illustrated panel 26 comprises aconductive loop 28 having an RFID chip 30 and a resistor or diode 32coupled thereto. “Panel” for purposes of this description means anymaterial to which the loop 28, chip 30, and resistor/diode 32 may beconnected, including the conveyor belt layer or layers, and which can bemade to travel around end pulleys 6, 8 in a manner commensurate with thefunctions of the invention herein described. The RFID chip 30 mayinclude at least one bore 31, preferably more than one, formed therethrough so that material 33 during the aforementioned vulcanization orother manufacturing process may extend through the bore(s) 31 and firmlysecure the chip 30 to the belt or the panel accordingly, as shown forexample in FIG. 8. The resistor or diode 32 may be used foridentification of open circuit, short circuit, or healthy panelconditions depending upon the current sensed by the RFID chip 30 as itpasses the interrogation unit 18. The interrogation unit 18 positionedon the conveyor structure will switch on the RFID chip 30 as it passesthe unit.

The RFID chip 30, in turn, will identify a measured current/resistanceand will transmit representative information back to the interrogationunit for analysis. This information may be used for sensing a variety ofconditions, including a rip condition. For example, the RFID chip 30 maysend a 1-bit to the interrogation unit to represent a good condition,and a 0-bit to represent a damage (rip) condition.

Referring again to FIG. 1, the interrogation unit 18 may be connected toa processing system 19, which in one embodiment is a programmable logiccontroller (PLC) rack system. For simplicity of connection, theinterrogation unit 18 may be connected to the processing system 19 viaan Ethernet switch 34. The processing system 19 may have a processor 36capable of executing instructions for analyzing the received signals andfor assessing a condition of one or more rip panels 26 based on thereceived signals. Thus, depending upon the magnitude of thecurrent/resistance sensed by the RFID chip 30 associated with aparticular rip panel 26, the processing system 19 can determine thecondition of that panel. The system may determine that a rip has beendetected, the severity of the rip, whether the panel itself has degradedover time, and so on. The executable instructions run by the processor36 may be customized by the user to analyze the signals and to triggeralarms (for cases in which slight rips have been detected), or to stopthe belt automatically in cases where large rips are detected.

In use of the disclosed system, a baseline reading from each RFID chip30 of each rip panel 26 may be obtained during a first cycle of the beltaround the pulleys 6, 8. During subsequent cycles the reading from eachRFID chip 30 may be compared with the original reading, and theoccurrence of any significant changes noted to determine whether thechange is indicative of a rip, or other condition in the belt.

For system embodiments in which multiple panels 26 are provided alongthe length of the conveyor belt 2, each panel 26 may have aresistor/diode 32 with a unique resistance to provide further level ofpanel identification. Alternatively, or in addition, the RFID chip 30may itself provide automatic identification of the individual panels 26.Examples of such identification information include the model,brand/original equipment manufacturer (OEM), age, repair history, ifany, and the like.

The conductive loop 28 may comprise any of a variety of conductivematerials, such as metal and non-metallic conductors. Examples ofsuitable metal conductors include copper and platinum. Non-limitingexamples of a suitable non-metallic conductor may include graphite, oran elastomeric conductive material such as that manufactured byNanoSonic, Inc., of Blacksburg, Va., sold under the trademark“METALRUBBER.” In other embodiments, the conductive loop can be in wireor ribbon form, as desired, which can be of suitably low resistivitysuch that it can be operated in conjunction with the RFID chip.

One substantial benefit of using a non-metallic conducting material toform the conductive loop 28 is that it is expected to add little to theoverall lateral stiffness of the conveyor belt 2. Conventional rippanels that utilize a plurality of laterally-oriented conductive metalwires can add substantial lateral stiffness to the conveyor belt. Thisincreased lateral stiffness may make it more difficult to “trough” thebelt (i.e., where the angled rollers of the conveyor structure force thebelt to conform to a V or U-shape in order to confine and carry the loadmaterial) in operation. In addition, forced troughing of the laterallystiff rip panels can cause premature failure of the rip panel due to thefatigue of repeated bending of the metal wires or cords.

Referring now to FIG. 6, an embodiment of a non-metallic rip panel 126is disclosed. Similar to the previously described rip panel 26, rippanel 126 comprises a plurality of conductive legs 128 that areelectrically coupled with an RFID chip 130. The RFID chip 130 of thisembodiment may have any or all of the characteristics of the RFD chip 30described in relation to FIG. 5. Thus, the RFID chip 130 may beconfigured to provide information to the interrogation unit 18 relatingto the integrity of one or more of the conductive legs 128 (e.g.;whether a partial or full rip has occurred in one or both), and may alsoprovide detailed information about the panel such as model, brand, age,repair history (if any), and the like. Thus, as the RFID chip 130 passesthe interrogation unit 18 it will be switched on. It will send a currentthrough the legs 128 and will send a digital bit to the interrogationunit indicating whether the circuit is closed (good) or open (bad). Itmay also provide an indication if one or more legs are only partiallyripped. Another RFID chip, like the one shown in association with thepreviously described rip panel 26, may provide information about thebelt.

FIG. 7 shows an alternative embodiment of a non-metallic rip panel 226incorporating a plurality of loops formed from a plurality of conductivelegs 228 electrically coupled to an RFID chip 230. The RFID chip 230 ofthis embodiment may have any or all of the characteristics of the RFIDchips 30, 130 described in relation to FIGS. 5 and 6. Thus, the RFIDchip 230 may be configured to provide information to the interrogationunit 18 relating to the integrity of one or more of the conductive legs228 (e.g., whether a partial or full rip has occurred in one or both),and may also provide detailed information about the panel such as model,brand, age, repair history (if any), and the like. An additional chip(not shown) may be associated with the panel 226 like that shown in FIG.5 with respect to the panel 26 of that embodiment.

In this embodiment, a single RFID chip 230 may be used to monitormultiple loops, simultaneously, and to provide the interrogation unitwith information regarding the ongoing integrity of the individual legs228 of the rip panel 226. This arrangement may provide more detailedinformation about a rip in the conveyor belt 2 as compared to previousembodiments due to its greater longitudinal extent (owing to themultiple-loop configuration). Thus, it may be possible to moreaccurately estimate the extent or length of a longitudinal rip in thebelt by knowing exactly how many legs 228 have been broken by the rip.As can be seen, one leg of each loop is connected to the RFID chip 230by a resistor (or diode) 232 having a unique resistance so that the RFIDcan immediately determine which leg has been breached by the rip.

Thus, as the RFID 230 passes the interrogation unit 18 it will beswitched on. It will send a current through the legs 228 and will send adigital bit to the interrogation unit indicating whether the circuit ishealthy or open/damaged. For the instant embodiment, the RFID may send asignal representing 1-1-1-1 to show a typical (i.e., good) condition.Alternatively, the RFID chip 230 may send a signal representing 0-1-1-1to show a damage condition in the first leg. This damage condition maythen be interpreted as a rip in the belt. Damage to more than one legwould be indicative of a longer rip. Unlike prior systems, therefore,the disclosed arrangement may also provide an indication if one or morelegs are only partially ripped.

In addition to the features described above, the system 1 may alsocomprise a camera 38 (FIG. 1) for transmitting visual informationregarding a top surface 12 of the belt cover to enable the user tocorrelate information provided by the system with a visual indication ofthe belt at a particular location. While the illustrated embodimentshows the camera 38 positioned beneath the belt, it will be appreciatedthat the camera could be positioned in any desired location to obtainimages of the belt top or bottom surfaces. In addition, multiple cameras38 may also be provided, including cameras having high definitioncapabilities. The cameras may be adjustable to pan a desired location,and they may also have zoom functionality to focus on a particular areaof interest. The signal from the camera 38 can be routed to theprocessing system 19 through the Ethernet switch 34. The camera 38 maybe controlled (e.g., to take continuous video images, or to take asnapshot at a targeted location) by the processing system 19. In oneembodiment, the processing system may signal the camera to automaticallytake a picture based on a triggering event (e.g., where a rip conditionis sensed).

The processing system 19 may also provide a connection to a belt controlsystem 40 to control the belt 2 as desired. Thus, the processing system19 may be used to instruct the belt control system 40 to slow the beltspeed and/or to stop a targeted portion of the belt at a specificlocation within the mine so that the belt can be inspected and/orrepaired. Alternatively, if the processing system 19 predicts animminent failure condition in the belt, the processing system 19 mayinstruct the belt control system 40 to immediately stop the belt 2regardless of its position.

The system 1 may further comprise user/operator display 42 for providinginformation regarding the status of the rip panels 26 in the system. Anyor all of the information in this display may be viewed locally, or itmay be transmitted to remote users via an appropriate datacommunications network such as a company's intranet, virtual privatenetwork (VPN), the Internet or the like to enable global viewing andcontrol of the system 1. The information can also be e-mailed to one ormore individuals (including photographs) so that a remote determinationcan be made regarding the damage.

It will be understood that the description and drawings presented hereinrepresent an embodiment of the invention, and are therefore merelyrepresentative of the subject matter that is broadly contemplated by theinvention. It will be further understood that the scope of the presentinvention encompasses other embodiments that may become obvious to thoseskilled in the art, and that the scope of the invention is accordinglylimited by nothing other than the appended claims.

1. A conveyor belt rip monitoring system, comprising: a conductive loop; an RFID chip electrically connected to said conductive loop; an RFID interrogator positioned to receive information about said conductive loop from said RFID chip; a processing system associated with said RFID interrogator for receiving a signal from the interrogator and processing said signal to obtain a measure of the integrity of said conductive loop; and a user interface for providing an indication of said integrity of said conductive loop to a user.
 2. A conveyor belt rip monitoring system according to claim 1, wherein the RFID interrogation unit can read and write to one RFID chip or a plurality of chips located on or in the belt.
 3. A conveyor belt rip monitoring system according to claim 1, wherein said conductive loop and said RFID chip are connected to a rip detection panel, said panel positioned between layers of a conveyor belt.
 4. A conveyor belt rip monitoring system according to claim 3, wherein said belt comprises a plurality of rip panels, said panels being positioned at approximately 200 foot intervals along said belt.
 5. A conveyor belt rip monitoring system according to claim 1, wherein a resistor or diode is electrically connected to said conductive loop and said RFID chip.
 6. A conveyor belt rip monitoring system according to claim 3, wherein a resistor or diode is electrically connected to said conductive loop and said RFID chip.
 7. A conveyor belt rip monitoring system according to claim 1, wherein said RFID chip further comprises at least one bore formed there through, material forming said belt or said panel extending through the bore such that the chip is firmly held, respectfully, to the belt or the panel.
 8. A conveyor belt rip monitoring system according to claim 1, wherein said processing system is a programmable logic controller (PLC) rack system, the interrogation unit being connected to said processing system via an Ethernet switch.
 9. A conveyor belt rip monitoring system according to claim 1, wherein the processing system further comprises a processor for executing instructions for analyzing signals received from said RFID interrogator and for assessing a condition of at least one rip panel or said conductive loop.
 10. A conveyor belt rip monitoring system according to claim 1, wherein said conductive loop is formed from a non-metallic conductive material.
 11. A conveyor belt rip monitoring system according to claim 1, wherein the RFID chip also provides to the interrogator information relating to a rip panel associated with said belt, the rip panel information comprising one or more of the members of the group consisting of: panel model information, panel brand/OEM information, panel age information, and panel repair history.
 12. A conveyor belt rip monitoring system according to claim 6, wherein the RFID chip also provides to the interrogator information relating to a rip panel associated with said belt, the rip panel information comprising one or more of the members of the group consisting of: panel model information, panel brand/OEM information, panel age information, and panel repair history.
 13. A rip monitoring system according to claim 6, wherein a user display is connected to the system for providing information about the status of the rip panel.
 14. A rip monitoring system according to claim 10, wherein said non-metallic conductive loop comprises a plurality of legs electrically coupled with the RFID chip.
 15. A rip monitoring system according to claim 14, further comprising a plurality of loops formed from a plurality of legs.
 16. A rip monitoring system according to claim 15, wherein one leg of each loop is electrically connected to the RFID chip by a resistor or diode having a different resistance so that the interrogator may distinguish each of the loops from another.
 17. A rip monitoring system according to claim 1, wherein said system further comprises at least one camera for transmitting visual information regarding the conveyor belt to a user.
 18. A rip monitoring system according to claim 1, wherein a belt control system is operably connected to said monitoring system for directly or indirectly changing the operation of the conveyor belt in response to said signal.
 19. A rip monitoring system according to claim 1, wherein said system is operably connected to a data communications network, said network comprising one or more members of the group consisting of a facility-wide monitoring system, an Intranet, a virtual private network and the Internet.
 20. A conveyor belt rip detection panel comprising: at least one panel; a conductive loop; and an RFID chip electrically connected to said conductive loop, wherein said loop and said chip are connected to said at least one panel.
 21. A rip detection panel according to claim 20, wherein said conductive loop is integrally formed with said panel.
 22. A rip detection panel according to claim 20, wherein a resistor or diode is electrically connected to said conductive loop and said RFID chip.
 23. A rip detection panel according to claim 20, wherein said RFID chip further comprises at least one bore formed there through, material forming said panel extending through the bore such that the chip is firmly held to the panel.
 24. A rip detection panel according to claim 20, wherein said conductive loop is formed from a non-metallic conductive material.
 25. A rip detection panel according to claim 21, wherein said conductive loop is formed from a non-metallic conductive material.
 26. A rip detection panel according to claim 24, wherein said non-metallic conductive loop comprises a plurality of legs electrically coupled with the RFID chip.
 27. A rip detection panel according to claim 26, further comprising a plurality of loops formed from a plurality of legs.
 28. A rip detection panel according to claim 27, wherein one leg of each loop is electrically connected to the RFID chip by a resistor or diode, each of the resistors or diodes having a different resistance so that the interrogator may distinguish each loop from another. 